Drive for barrel pumps and engines



March 26, 1963 R. LUCIEN 3,082,697

DRIVE FOR BARREL PUMPS AND ENGINES Filed March 21. 1961 IN VE N TOR RENE LUC IE N United States Patent Ofiice 3,082,697 Patented Mar. 26, 1963 3,082,697 DRIVE FOR BARREL PUMPS AND ENGINES Ren Lucien, Neuilly-sur-Seine, France, assignor to Socit a Responsabilit Limite: Recherches Etudes Production R.E.P., Paris, France, a corporation of France Filed Mar. 21, 1961, Ser. No. 97,300 Claims priority, application France Apr. 6, 1960 1 Claim. (Cl. 103162) The invention relates to barrel pumps and engines, that is to say pumps and engines which have a plurality of cylinders arranged parallel to each other and to the general axis of the machine. The invention relates more particularly to an improvement in the drive of the pistons of barrel pumps and engines, the pistons of which are actuated by a plate (or a cam, or an abutment) mounted obliquely on the pump shaft. It should be clearly understood that the invention is concerned both with pumps and engines in which the barrel rotates and the inclined plate is fixed and also pumps and engines in which the barrel is fixed and the inclined plate rotates.

In the known types of barrel pumps and engines, the guiding of each piston is necessarily limited, since it is provided solely by its bearing surface in its cylinder. This limitation imposed on the guiding of the piston is a drawback, because the thrust (for delivery) and the pull (for suction) of the piston are necessarily oblique with respect to the axis of the piston, since these efforts are provided by the inclined plate. This inherent defect becomes serious and even prohibitive in certain applications such as, for example, with machines working at high pressure and/ or high speeds of rotation, the limited guiding of the piston becoming inadequate with respect to the magnitude of the alternating transverse reaction produced by the obliquity of the plate.

The invention has as an object the elimination of this disadvantage or this defect, by providing the piston with a guiding and bearing surface which is considerably more extensive, and further by bringing the point of application of one of the two mechanical drives of the piston (the suction or delivery drive) into the actual interior of the said bearing surface, the other drive of the piston being located quite close to the said bearing surface. A further object of the invention is to provide an improved pump structure which is compact and readily manufactured.

In accordance with the invention, the pump or the engine is provided with a barrel in two parts, thus enabling the providing of the piston of each cylinder with two guide-bearings relatively spaced apart from each other and thereby insuring a considerable improvement in guiding. In addition, the invention provides for housing one of the two piston drives, for example its suction drive, between the said guide-bearings, and for locating the other piston drive, for example its delivery drive, as close as possible to one of these guide-bearings.

These arrangements, and also the corresponding advantages, will be described in more detail in the text which follows below, reference being made to the sole FIGURE of the accompanying drawing, given by way of example and Without any implied limitation, which illustrates the application of the invention to a hydraulic pump with a rotating barrel.

The sole FIGURE is an axial cross-section of the pump, certain members being however shown without being sectioned for the sake of clearness.

The pump comprises a stator 1 formed with a fixed shaft 2 and an end-plate 3 incorporating the oblique plate 4. The rotor, rotating on the bearing 5 and in the bearing 6, is driven by a splined shaft 7 provided with fluid-tight sealing devices 8 and 9. It comprises a plurality of cylinders 12 (for example 7 in number), with their pistons 13. These cylinders 12 are provided with orifices 14, constituting an admission and delivery distributor with a slide-face 17 orientatable on a spherical bearing surface 13 by means of a three-ball suspension 19. According to the invention, the barrel 15 of the cylinders 12 is in two parts 21 and 22 located with respect to each other, for example, by three studs 23 and assembled, for example, by three bolts 24, the part 21 being bored at 25 in known manner to constitute the cylinder 12, and the part 22 being bored to form the second bearing 26 of the piston 13. It will be observed that the relatively large space between the guide-bearings 25 and 26 of the piston 13 insures accurate guiding, since the bearing surface is considerably increased with respect to the single conventional bore 25.

In addition, according to the invention, one of the two mechanical drives of each piston 13, in this case the suction drive, has its point of application on the piston located between the two guide-bearings 25 and 26. For example, the rotor 15 comprises a cap 27 mounted on a spherical head 28 of the body 21 and held against a spring 29. The cap 27 controls the pistons 13 on the suction stroke by means of rings 30. The spring 29, on the one hand applies the barrel against the slide-face 17 and forces the latter against its spherical bearing surface 18 and, on the other hand, the spring 29 applies the shoes 31 with spherical heads 32 of the pistons 13 against the oblique plate 4. The drive of the pistons 13 on the delivery stroke is insured, in known manner, by the oblique plate 4 and the shoes 31 with spherical heads 32. In accordance with the invention, this second mechanical drive of each piston is placed as close as possible to the body 22 of the barrel 15 (as can particularly be seen in the lower part of the figure, which corresponds to the top dead-center), this arrangement being made possible by the transfer of the other mechanical drive of each piston. As a consequence, the overhang of the pistons 13 caused by their operation by the inclined plate 4, is reduced to the lowest possible minimum, which permits a much greater inclination of the inclined plate 4 on the general axis, and thus an operation at much higher pressures.

What is claimed is:

Pumping apparatus comprising a barrel defining an axis and provided with a plurality of cylinders parallel to said axis and located in a circle thereabout, a plate having a surface inclined relative to said axis and axially spaced from said barrel, means supporting said barrel and plate for relative rotational displacement, said barrel in cluding a first portion defining said cylinders and a second portion defining bores coaxial to said cylinders and axially spaced from the same, pistons slidably accommodated in said cylinders and bores and including extremities adjacent said plates, said extremities defining respective sockets, shoes having fiat surfaces slidably engaging said plate and including spherical heads rotatable in said 3 4 sockets, said displacement of said plate being effective References Cited in the file of this patent through said shoes and heads to drive said pistons, said UNITED STATES PATENTS pistons including spherical portions between said cylinders and bores, a cap including rings engaging said 2,780,170 Stfiyke et 1957 spherical portions, a body supported on and displaceable 5 2,930,321 Nollin 19 axially relative to said barrel, a spring between said body and barrel to urge said cap and rings against said spheri FOREIGN PATENTS cal portions and thereby said pistons and shoes against 52 ,233 Germany May 13 1931 said plate, said body including a spherical bearing sup- 527 35 Germany J 4 193 porting said cap for universal pivoting movement, said 10 1,183,821 France July 15 5 cylinders and bores defining a space therebetween, said spherical bearing being confined to said space. 

